One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Spirit Lake you can figure out when you can plant tree onions by checking out the USDA zone info.

Planting Calendar for Tree onions

Frost tolerance for tree onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Tree onions do well in mild cold which tells us that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant tree onions in Spirit Lake is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant tree onions and expect a good harvest is probably August. Any later than that and your tree onions may not have a chance to grow to maturity. Starting your tree onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Spirit Lake. It might get as low as -20°F during the coldest months of winter.

Always keep in mind that USDA zone info for Spirit Lake is not always accurate and the actual date of last frost is different every year. Half of the time in Spirit Lake there is a last frost after April 15 so always be ready to protect your tree onions in the event of a surprise late frost.

USDA Zone Info for Spirit Lake

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Spirit Lake

You may be interested in your other planting guides for Spirit Lake.